The State Wetlands Protection Act protects beaches. Beaches include coastal beaches, barrier beaches, and tidal flats. Coastal beaches are composed of unconsolidated sediment (sand, clay, or gravel) that moves with storm and/or wave action. The regulations define coastal beaches as a "gently sloping shore of a body of salt water..that extend from the mean low water line landward to the dune line, coastal bank line, or the seaward edge of manmade structures when these structures replace one of the above lines…" A definition of coastal beach can be found in the State regulations at CMR 10.27(2).
A barrier beach is "a narrow, low lying strip of land generally consisting of coastal beaches and coastal dunes extending roughly parallel to the trend of the coast…separated from the mainland by a narrow body of fresh, brackish or saline water or a marsh system. It may be joined to the mainland at one or both ends." A definition of barrier beach can be found in the State regulations at CMR 10.29 (2).
A tidal flat is a "nearly level part of a coastal beach which usually extends from the mean low water line landward to the more steeply sloping face of the coastal beach". A definition of tidal flat can be found in the State regulations at CMR 10.27 (2)(b).